For me, it was difficult to choose between MA RS6 and B&W 603S3 after the listening to them and reading all the reviews. First, the two brands were demo'ed by different dealers, with totally different room dimensions, placement of speakers, driving amp/receiver. Secondly, it was difficult to assess their acoustic engineering from information at their website and reviews.
Speakers I auditioned include: Martin Logan, Def Tech, Vienna Acoustics, Sonus Faber, B&W, Paradigm, and Monitor Audio, from bookshelf type to floorstanders, middle of the line to top of the line speakers of each manufacturer.
To make a long story short, eventually my three picks were Vienna Acoustics Bach Grand, B&W 603 S3, and Monitor Audio RS6 or RS8. There were some unknowns: engineering, power handling (the specs are not based on the same standards), speaker aging, acoustical output. In the end I just quit comparing and told myself that comparison of speakers is not a science - what if one speaker sounds better than the other but actually does not compare to the intent of the original artist.
In the end, I threw all comparisons out the window - I just choose to confirm if MA RS6 will do, based on my music selection consisting of voices and instruments that are very familiar to me, played at the volume level I prefer (about 70-75db). No movies were considered since I have an entire 5.1 set of Boston Acoustics CR series for movies.
The verdict: I confirmed that MA RS6 is very good, based on my musical selection.